Memcache::getVersion
Be careful to use Memcache::decrement() and never Memcache::increment() with a negative value.
The check that prevents Memcache::decrement() from going negative is not in place with Memcache::increment(), so you can end up with a garbage integer on the order of 18 quintillion stored in place of the expected value.
Memcache::increment
(PECL memcache >= 0.2.0)
Memcache::increment — Increment item's value
Opis
int Memcache::increment
( string $key
[, int $value = 1
] )
Memcache::increment() increments value of an item by the specified value. If item specified by key was not numeric and cannot be converted to a number, it will change its value to value. Memcache::increment() does not create an item if it doesn't already exist.
Also you can use memcache_increment() function.Informacja: Do not use Memcache::increment() with items that have been stored compressed because subsequent calls to Memcache::get() will fail.
Parametry
- key
-
Key of the item to increment.
- value
-
Increment the item by value.
Zwracane wartości
Returns new items value on success lub FALSE w przypadku błędu.
Przykłady
Przykład #1 Memcache::increment() example
<?php
/* procedural API */
$memcache_obj = memcache_connect('memcache_host', 11211);
/* increment counter by 2 */
$current_value = memcache_increment($memcache_obj, 'counter', 2);
/* OO API */
$memcache_obj = new Memcache;
$memcache_obj->connect('memcache_host', 11211);
/* increment counter by 3 */
$current_value = $memcache_obj->increment('counter', 3);
?>
Zobacz też:
- Memcache::decrement() - Decrement item's value
- Memcache::replace() - Replace value of the existing item
add a note
User Contributed NotesMemcache::increment
ian at blip dot fm
30-Jun-2009 11:28
30-Jun-2009 11:28
jay dot paroline at escapemg dot com
13-May-2009 01:34
13-May-2009 01:34
Instead of checking the value before incrementing, you can simply ADD it instead before incrementing each time. If it's already there, your ADD is ignored, and if it's not there, it's set.
If you add($memcacheKey, 0) and then increment($memcacheKey, 1) in that order, you avoid all possible race conditions. If two threads are running this code concurrently, you will always end up with your value being 2 no matter which order the threads execute in.
Anonymous
13-May-2009 01:16
13-May-2009 01:16
Please note:
If the key does not exist, memcache does NOT return false (as you might expect) but 0.
You won't get any hint that the key did not exist and still does not exist and that nothing was incremented.
15-Jun-2005 07:54
if no variable exists, even if you specify an increment value, the result will be null.
if you're using this for a mutex, chk if its null, and if so, then ADD the variable.